Trumpsaid he was ordering a review by the Justice Department and other agencies and "if appropriate, the culprit should be prosecuted to the fullest extent of the law".

Police in Manchester, England, made a decision to stop sharing some intelligence with the USA after details from their ongoing terrorism investigation were apparently leaked to the American press, the city's mayor told CNN.

At least 22 people were killed and dozens others wounded when a suicide bomber blew himself up at the end of a concert by USA singer Ariana Grande outside the Manchester Arena.

This comes after unauthorized leaks splashed across United States media following the Manchester terrorist attack, according to Reuters, citing Britain's most senior counter terrorism officer.

Visiting the military alliance's new $1.2 billion headquarters with fellow leaders later, Trump led a moment's silence for the victims of what he described as "a barbaric and vicious attack on our civilisation". "It is absolutely understandable the distress and upset this has caused those families, who are already suffering as everybody can imagine".

Salman Abedi was a 22-year-old born in Manchester to Libyan parents, and a former University of Salford student.

Speaking on the Today Programme on Thursday, former Metropolitan Police Commissioner Sir Ian Blair, called the leaking of information in the USA a "grievous breach", but said the same thing had occurred after the July 7, 2005 London terror attack that claimed 52 lives.

The National Police Chiefs' Council (NPCC) said the leak of the pictures breached trust and "undermines our investigations and the confidence of victims, witnesses and their families". "This is until such time as we have assurances that no further unauthorised disclosures will occur", said the counter-terrorism source.

"From the day we started putting the Dangerous Woman tour together", she wrote, "I said that this show, more than anything else, was meant to be a safe space for my fans".

Manchester police have not commented since, although a national counterterrorism official said in a statement that his agency has received "fresh assurances" from global partners and is working closely with worldwide law enforcement groups, including the U.S. He died at the scene. The terror group claimed responsibility for the attack.

Their arrest followed that of Salman's older brother, 23-year-old Ismail, in Manchester. Details of their alleged connection to the bombing have not been revealed.

Special Deterrent Force spokesman Ahmed bin Salem said Thursday that Salman Abedi's mother and three of his siblings in Libya were summoned for questioning. "These leaks have been going on for a long time and my administration will get to the bottom of this", he said.

Shortly after the memorial service, Queen Elizabeth arrived at Royal Manchester's Children's Hospital to visit some of the 64 people injured in the attack.